Construction of core–shell semiconductor heterojunctions and plasmonic metal/semiconductor heterostructures represents two promising routes to improved light harvesting and promoted charge separation, but their photocatalytic activities are respectively limited by sluggish consumption of charge carriers confined in the cores, and contradictory migration directions of plasmon‐induced hot electrons and semiconductor‐generated electrons. Herein, a semiconductor/metal/semiconductor stacked core–shell design is demonstrated to overcome these limitations and significantly boost the photoactivity in CO2 reduction. In this smart design, sandwiched Au serves as a “stone”, which “kills two birds” by inducing localized surface plasmon resonance for hot electron generation and mediating unidirectional transmission of conduction band electrons and hot electrons from TiO2 core to MoS2 shell. Meanwhile, upward band bending of TiO2 drives core‐to‐shell migration of holes through TiO2–MoS2 interface. The co‐existence of TiO2 → Au → MoS2 electron flow and TiO2 → MoS2 hole flow contributes to spatial charge separation on different locations of MoS2 outer layer for overall redox reactions. Additionally, reduction potential of photoelectrons participating in the CO2 reduction is elaborately adjusted by tuning the thickness of MoS2 shell, and thus the product selectivity is delicately regulated. This work provides fresh hints for rationally controlling the charge transfer pathways toward high‐efficiency CO2 photoreduction.

Construction of photocatalytic systems with spatially separated dual cocatalysts is considered as a promising route to modulate charge separation/transfer, promote surface redox reactivities, and prevent unwanted reverse reactions. However, past efforts on the loading of spatially separated double‐cocatalysts are limited to hollow structured semiconductors with inner/outer surface and monocrystalline semiconductors with different exposed facets. To overcome this limitation, herein, enabled by a unique stacked photocatalyst design, a facile and versatile strategy for spatial separation of redox cocatalysts on various semiconductors without structural and morphological restriction is demonstrated. The smart design begins with the deposition of light‐harvesting semiconductors on reduced graphene oxide (rGO) nanosheets, followed with the coverage of Ni(OH)2 outer layer. The ternary photocatalysts exhibit superior activities and stabilities of H2O oxidation and selective CO2‐to‐CO reduction, remarkably surpassing other counterparts. The origin of the enhanced performance is attributed to the synergistic interplay of rGO@Ni(OH)2 reduction cocatalysts surrounding the semiconductors and Ni(OH)2 oxidation cocatalysts directly supported by the semiconductors, which mitigates the charge recombination, supplies highly active and selective sites for overall reactions, and preserves the semiconductors from photocorrosion. This work presents a new approach to regulating the position of dual cocatalysts and ameliorating the net efficiency of photoredox catalysis.

Step‐scheme (S‐scheme) heterojunctions have exhibited great potential in photocatalysis due to their extraordinary light harvesting and high redox capacities. However, inadequate S‐scheme recombination of useless carriers in weak redox abilities increases the probability of their recombination with useful ones in strong redox capabilities. Herein, a versatile protocol is demonstrated to overcome this impediment based on the insertion of nano‐piezoelectrics into the heterointerfaces of S‐scheme heterojunctions. Under light excitation, the piezoelectric inserter promotes interfacial charge transfer and produces additional photocarriers to recombine with useless electrons and holes, ensuring a more thorough separation of powerful ones for CO2 reduction and H2O oxidation. When introducing extra ultrasonic vibration, a piezoelectric polarization field is established, which allows efficient separation of charges generated by the embedded piezoelectrics and expedites their recombination with weak carriers, further increasing the number of strong ones participating in the redox reactions. Encouraged by the greatly improved charge utilization, significantly enhanced photocatalytic and piezophotocatalytic activities in CH4, CO, and O2 production are achieved by the designed stacked catalyst. This work highlights the importance in strengthening the necessary charge recombination in S‐scheme heterojunctions and presents an efficient and novel strategy to synergize photocatalysis and piezocatalysis for renewable fuels and value‐added chemicals production.